Method of producing a sphere with a hole therethrough



2,941,290 METHOD OF PRODUCING A SPHERE WITH A HOLE THERETHROUGH FiledJan. 11, 1955 L. R- HEIM June 21,- 1960 2 Sheets-Sheet 1 3x3, INVENTORin; m

ATTO RN EYS.

L. R. HEIM 2,941,290 METHOD OF PRODUCING A SPHERE WITH A HOLETHERETHROUGH June 21, 1960 Filed Jan. l1, 1955 2 Sheets-Sheet 2 INVE TORBY United States Patent METHOD OF PRODUCING A SPHERE WITH A HOLETHERETHROUGH Lewis R. Heim, Fairfield, Conn., assignor to The HeimCompany, Fairfield, Conn, a corporation of Connecticut Filed Jan. 11,1355, Ser. No. 481,069

3 Claims. ((31. 29-545) This invention relates to a method of producinga spherical member or ball with a hole therethrough, and has for anobject to provide an improved method for sizing and forming a sphericalmember to the proper diameter and shape from forms or .blanks made frommetal or other suitable ductile material.

A'further object is to provide such a method in which an undersize blankor form is made from metal or other suitable material and an undersizedhole produced therethrough, and then this blank or form is expanded andsized to a predetermined diameter and form.

With the foregoing and other objects in view, I have devised theconstruction illustrated in the accompanying drawings forming a part ofthis specification. It is, however, to be understood the invention isnot limited to the specific details of construction and arrangementshown, but may embody various changes and modifications within the scopeof the invention.

In these drawings:

Fig. 1 is a longitudinal section showing an expanding and forming dieset in a power press for carrying out this method and showing the diesin separated or retracted position prior to the expanding and sizingoperation;

Fig. 2 is a similar section showing them together at the completion ofor after performing the expanding and sizing operation;

Fig. 3 is a side view of a portion of a metal bar or rod indicating howthe blanks or forms for producing the spherical member may be machinedfrom this bar;

Fig. 4 is a side view of one form of blank which may be used andmachined from the bar;

Fig. 5 is an end view thereof looking toward the bottom of Fig. 4;

Fig. 6 is a side view showing another form of blankwhich may be used;

Fig. 7 is an end view thereof looking toward the bottom of Fig. 6;

Fig. 8 is a side view of the completed spherical member or ball afterexpanding and sizing the machined form or blank;

Fig. 9 is an end view thereof looking toward the bottom of Fig. 8;

Fig. 10 is a section showing another arrangement of dies which may beused in this method and showing them in the separated position, and

Fig. 11 is a section of the dies of Fig. 10 showing them in the closedposition after performing the expanding and sizing operation.

In forming a substantially spherical member or ball by this method, ablank or form may be provided by a number of different ways. One is tomachine it from flats 16 at its opposite ends. The blankof Figs. 6 and 7a bar or rod 10' of metal, as indicated in Fig. 3, the 7 blank or formbeing indicated at 11 circular in cross section and having an outersurface 12 convexly curved longitudinally of the blank and with alongitudinal opening 13 of a given size therethrough, the blank beingthen cut ofi from the rod at the point .14 and used in this improvedexpanding and sizing method to form the is the ellipsoidal blank 11 ofFig. 3,with the outer ellipsoidal surface 12 and having the opening 13therethrough. This blank preferably also has flats 17 at its oppositeends.

Afterthese undersized blanks or forms are made they are expanded andsized to a predetermined diameter and form by the dies and operatingmeans therefor shown in Figs. 1, 2, l0 and 11. Referring first to Figs.1 and 2, the die set is shown adapted for mounting in a power press (notshown) for operation thereby, and comprises a die shoe 18 provided witha recess 19 in which is seated the lower die block 20 and which may beheld in place by a set screw 21. This die block is provided with arecess or socket 22 in which is seated a lower die 23 which may belocked in place by a set screw 24. The shoe and block 18 and 20 areprovided with a vertical opening 25 in which is a coil spring 26pressing at its upper end against the under side of the head 27 of aslidable pilot 28, the head 27 being in the opening in the block and itsbody portion in an opening 29 in the die 23. The outward end of thispilot is reduced in diameter as indicated at 30, and in the top of thedie is formed a substantially semispherical recess 31, the opening 29leading to the bottom of this recess.

The upper die and. its mounting comprises the die 32 similiar to andover the die 23, andhaving in its lower end a substantiallysemispherical recess 33 similar to the recess 31 and in alignmenttherewith. This die has a passage or opening 34 therethrough in which isslidably mounted a punch 35 having a reduced and tapered lower end 36extending into the socket 33. This die is mounted in a recess or socket37 in the lower end of a hollow sleeve 38, and may be secured by a setscrew 32a. Mounted for limited longitudinal sliding movement in thissleeve 38 is a cylindrical block 39 forming a carrier for the punch 35,this punch having an enlarged threaded upper end 40 screw threaded intothe lower end of block 39, and may be secured in adjusted positions by aset screw 41. This block 39 is provided with a transverse elongated slot42 extending therethrough in which is slidable a flat bar 43 pnojectingat its opposite ends through openings 44 in the sides of the sleeve 38,and springs 45 connected to this bar tend to lift it and the sleeve 38.Transverse pins 46 may be mounted in the bar 43' to keep it centered inthe sleeve 38. The block 39 is provided with a longitudinal passage 47in which is a plunger rod 48 normally engaging at its lower end on thetop of the bar 43.

In the operation of expanding and sizing the blanks 11 or 11a, the blankis placed in the recess 31 in the lower die 23, this recess and therecess 33 being made to the size and shape desired for the finished ballor sphere, and is larger than the blank by the desired amount to providethe clearance space 49 about the blank. In this position the pilot 38 isheld in its upper position by the spring 26 with its upper reduced end30 in and fitting the hole 13 provided in the blank. This properlycenters the blank in the die and holds it in the centered and uprightposition in alignment With the recess 33 in the upper die and the lowerend of the punch 3 block 39 bar 43 and plunger 48 move downwardlytogether under action of the power press, until the lower end of the die32 rests on top of the lower die 23, as shown in Fig. 2, if the ball isto be expanded :from the inside by action of the plunger 35 only.However, if theba'll .is being compressed axially, then die .32 stopsits downward travel when'the face 17 .of the ball is engaged by the topwall 33a of cavity 33 in the die 32. Die 32 resumes its downward travelwhen shoulder 39a on block 39 hits the upper end 38a of sleeve 38. Thedie 32 is then carried down under power tolongitudinally compress theball until the lower end of die 32 rests on top of lower die 23. Thisarrests downward movement 'of the die 32, the sleeve 38, bar 43 andplunger 48. Then the block 39 and the punch 35 continue to movedownwardly forcing the tapered lower end 36 of the punch through theopening 13 in the blank 11, and the .pu'nch is carried far enough topass the tapered end portion 36 :of punch 35 through the blank and untilits cylindrical ibody'portion 35a also passes into and through theblank, as indicated in Fig. 2, the punch in this movernen't forcing thepilot 28 downwardly out of the openingtin the blank. As the body 35a ofthe punch 35 is of larger diameter than the hole 13 of the blank, itwill expand this blank into the recesses 31 and 33, which are now linedup in the two dies, thus-filling these recesses and forming and sizingthe outer surface of the blank'to the size and shape of these recesses.This expanding and sizing operation may be performed solely by theexpanding action of the punch passing through the blank or previouslymachined form, or the dies could be so designed that there islongitudinal pressure applied to the blank, thus giving an expandingaction on the blank by pressure on the opposite ends 17 of the blank,while the side walls of the opening 13 are held by the punch 35 againstcontracting.

After the expanding and sizing operationis completed, the entire upperdie assembly moves upwardly to predetermined stops 43a, carrying theformed ball with it. The stops 43a are comprised of adjustable setscrews in the frame of the press and these screws or stops engage bar 43while the die set is moving upwardly, thus holding bar 43, sleeve 38 anddie 32 against further upward movement. Plunger 48 and punch 35 continuein upward motion, thus stripping formed ball 50 from punch 35, afterwhich plunger 48 and punch '35 continue upward movement until fullupward position is attained, as shown in Fig. 1, in preparation for thenext sizing and expanding operation. At the termination of the strippingoperation the expanded and sized, and therefore the completed, formedball or sphere 50 with its spherical outer surface 52 falls from thepunch 35 and recess '33 and may be removed from the operating area. Thisball member may be used as formed, or it may be heat-treated, or itcould be'tumbled in a tumbling barrel for a better surface finish. Stillfurther, this ball member could be ground-and lapped to a high degree ofprecision, especially when it is used in a self aligning hearing.

Although as stated the undersized machined form or blank could bemachined with an outer substantially spherical surface 15 as shown onblank 11a of Figs. 4 and 5, it is preferably somewhat elongated as shownin Figs. 6 and 7 and of a substantially ellipsoidal shape, or with itsside walls 12 longitudinally convexly curved on a longer and flattercurve than would be a spherical surface. This is because with this formthe variations between the thicknesses of the side walls of the blankbetween the center and the ends is less at different transverse planes,and the metal has less tendency to pile up, so to speak, at the centerof the blank than with the spherical surface. In other words, it tendsto expand more evenly throughout the length of the blank. The

outer curved surfaces 12 and 15 could be carried to the edges of thehole 13, but it is preferred to provide the starting flats 16 and 17 atthe opposite ends to prevent crushing by the longitudinal pressure ofthe dies, and also to prevent extrusion of the metal into the dies.

In Figs. 10 and 11 is shown a modified arrangement of dies for carryingout this method. Here the dies 53 and 54 corresponding to the dies 23and 32 are not provided with the recesses 31 and 33. Therefore theundersized machined blank or form 11 or 11a is expanded by either thepunch 35, or the longitudinal pressure of the dies on its opposite ends,or both together, with no external holding of its longitudinallyconvexed outer side walls or surfaces 12 or 15. Otherwise the method andaction of expanding and sizing the undersized machined blank is the sameas that described in connection with Figs. 1 and 2.

Although in Fig. 3 the blank or form '11 is .shown as being machinedfrom a bar or rod, thisis only one way of forming this blank. It is tobe understood it may be made by othermethods, such, for example, as byhiquetting .and sintering powdered metal, cold or hot forging, molding,and similar methods.

Having thus set forth the nature of my invention, I claim: 1

1. The method of making a substantially spherical member with a holetherethrough which comprises making or forming on bar stock of suitableductile material an undersized form with a cylindrical openingtherethrough, a convexly curved outer surface, and side walls in whichthe variation in thickness between the center and the ends is less thanit would be if the surface were spherical, cutting the form from thestock and expanding the form radially by compressing it longitudinallywhile supporting the side walls of the opening :against inward movement,whereby expansion occurs more evenly throughout the length of theopening than it would if the surface were spherical.

2. The method of claim 1, in which the form is expanded into apreformed'recess in a dieset.

3. The method of making a substantially spherical member with a holetherethrough which comprises making or forming from a suitable ductilematerial an undersized form with a cylindrical opening therethrough, aconvexly curved outer surface, and side walls in which the variation inthickness between the center and the ends is substantially less than itwould be-if the surface were spherical, and simultaneously decreasingthe length of the form and expanding the form radially by compressing itlongitudinally while forcing through-the openinga punch of largerdiameter than that of the opening, whereby radial expansion occurs moreevenly throughout the length of theopening than it would if the surfacewere spherical.

References Cited in the file-of this patent UNITED STATES PATENTSHamilton Mar. M, 1953

